Conventionally, frequencies are exclusively assigned to systems and carriers in a fixed manner according to specific respective purposes. However, in recent years, as the bands of new systems widen, as the new radio interfaces are becoming sophisticated, and as the standardized speed increases, frequency resources are drying up. It is becoming difficult to assign a new frequency to a new system exclusively in a fixed manner as in the past.
Regarding this problem, in the technique shown in the non-patent document 1, a method is proposed for using software radio and cognitive support pilot channel (CPC: cognition supporting pilot channel).
[Non-patent document 1] “An alternative concept to scanning process for cognitive radio systems: technical and regulatory issues”, Martigne, P.; Moessner, K.; Cordier, P.; Ben Jemaa, S.; Houze, P.; Agusti, R.; Deschamps, B.; Bender, P.; Jeanty, L.; Bourse, D.; 16th IST Mobile and Wireless Communications Summit, 2007. 1-5 Jul. 2007, pp. 1-5